1. Field of the Invention
The present invention relates to an information processing apparatus and method, and more particularly to an information processing apparatus and method which enable a C/N (Carrier to Noise) ratio to be detected at high speed by detecting the difference between levels at a code judgment point (a place where an eye is open in eye pattern observation) and a code change point (zero cross point).
2. Description of Related Art
When receiving radio waves and detecting a C/N ratio from received signals, it has been a conventional practice to detect an error occurring during demodulation, or a vector error from an ideal symbol constellation, that is, a deviation from an ideal symbol point.
However, to determine a C/N ratio by thus detecting an error occurring during demodulation, or a vector error from an ideal symbol constellation, that is, a deviation from an ideal symbol point, received signals must be temporarily demodulated. Therefore, since carrier frequency synchronization must be completely taken, a C/N ratio is time-consuming to detect, so that there has been a problem that it is difficult to detect a C/N ratio at high speed.
The present invention has been made in view of such a situation and an object thereof is to detect a C/N ratio at high speed.
An information processing apparatus according to one aspect of the present invention comprises: amplitude value detection means for detecting an amplitude value from a received signal; code judgment detection means for detecting a code judgment point based on an amplitude value detected by the amplitude value detection means; code change point detection means for detecting a code change point based on an amplitude value detected by the amplitude value detection means; and noise detection means for detecting signal noise from a code judgment point detected by the code judgment detection means and a code change point detected by the code change point detection means.
An information processing method according to another aspect of the present invention comprises: an amplitude value detection step for detecting an amplitude from a received signal; a code judgment detection step for detecting a code judgment point based on an amplitude value detected by the amplitude value detection step; a code change point detection step for detecting a code change point based on an amplitude value detected by the amplitude value detection step; and a noise detection step for detecting signal noise from a code judgment point detected by the code judgment detection step and a code change point detected by the code change point detection step.
In the information processing apparatus according to one aspect of the present invention and the information processing method according to another aspect of the present invention, an amplitude value is detected by a received signal, a code judgment point is detected based on the detected amplitude value, a code change point is detected based on the detected amplitude value, and signal noise is detected from the detected code change judgment point and code change point.
According to an information processing apparatus, an information processing method, and an information medium of the present invention, since a code judgment point and a code change point are detected from a received signal, signal noise can be estimated.